Maintenance of Wakefulness Test (MWT)

The Maintenance of Wakefulness Test (MWT) is used to assess your ability to stay awake in monotonous situations.

The Maintenance of Wakefulness Test is used, for example, to evaluate your eligibility to obtain or retain a driver’s license if you have a condition that causes excessive daytime sleepiness, such as sleep apnea or narcolepsy.

If you already have a driver’s license, your driving ability may also be assessed through a health-based driving evaluation, which evaluates your ability to stay awake during monotonous, prolonged highway driving. However, if you are applying for a driver’s license for the first time, the Maintenance of Wakefulness Test is the only available option.

Important

Details of the examination may vary between units. Always read the patient instructions you receive well in advance of the examination.

How do I prepare for the Maintenance of Wakefulness Test?

Before the test, you will receive a sleep diary in which you will mark your sleep and wake times over several days. Try to maintain a regular sleep schedule during the week leading up to the examination. It is important that you sleep normally the night before the test, preferably at least 6 hours.

To ensure good electrode contact, your hair should be clean and dry. Do not use hair styling products.

Patient instructions for examinations

What happens during the Maintenance of Wakefulness Test?

During the test, your task is to remain awake for 40 minutes while sitting still in a reclining chair with your eyes open in a dimly lit room. There are four test sessions during the day (between 8:00 and 15:00), each spaced two hours apart. If you fall asleep during a session, you will be awakened after no more than 1.5 minutes.

A healthy person typically remains awake for about 30 minutes during the test, but there is considerable variation. About 5% of healthy individuals fall asleep in less than 13 minutes.

A wakefulness duration of 20 to 33 minutes is considered sufficient for safe driving. For professional driving, a threshold of up to 40 minutes—remaining awake throughout all test sessions—has been recommended.

What should I be aware of after the Maintenance of Wakefulness Test?

The test does not require follow-up and does not impose any restrictions on normal daily activities.

The physician who referred you for the examination will inform you of the results and the next steps in your treatment. If you do not have a scheduled appointment or call time, please contact your care unit.

Are there any risks associated with the Maintenance of Wakefulness Test?

The examination is painless and involves no risks.